A REVIEW OF THE PALEO-HYDROLOGICAL AND GEOMORPHOLOGICAL CHARACTER OF LAKE NAM CO, SOUTH-CENTRAL TIBET

The endorheic Lake Nam Co, south Eastern Tibetan Plateau, was selected to investigate the interrelationbetween drainage basin processes, especially post-glacial glacier decay, and lake level fluctuations. Landforms of thedrainage basin are highly influenced by tectonics, superimposed by fluvial and periglacial processes, and locally by glacialand eolian processes. Thus,geomorphological features and hydrological characteristics were compiled for the lake-basin toprovide an overview of the landscape character. Data show that during the Last Glacial Maximum melt water from themountains accumulated fluvial deposits in the foreland. Concurrently, an increase of the lake level occurred which ispresently shown by a cliff line all around Nam Co with its base approximately 29m above the present lake level. TheHolocene decrease of the lake level is traced by beach ridges. As Nam Co is an endorheic lake post-glacial water loss has tobe primarily explained by evaporation and moisture conditions. However, more detailed conclusions on quantitative andchronological patterns of both factors, melt-water input and evaporation output, still remain to be drawn.

The endorheic Lake Nam Co, south Eastern Tibetan Plateau, was selected to investigate the interrelation between drainage basin processes, especially post-glacial glacier decay, and lake level fluctuations. Landforms of the drainage basin are highly influenced by tectonics, superimposed by fluvial and periglacial processes, and locally by glacial and eolian processes. Thus,geomorphological features and hydrological characteristics were compiled for the lake-basin to provide an overview of the landscape character. Data show that during the Last Glacial Maximum melt water from the mountains accumulated fluvial deposits in the foreland. Concurrently, an increase of the lake level occurred which is presently shown by a cliff line all around Nam Co with its base approximately 29m above the present lake level. The Holocene decrease of the lake level is traced by beach ridges. As Nam Co is an endorheic lake post-glacial water loss has to be primarily explained by evaporation and moisture conditions. However, more detailed conclusions on quantitative and chronological patterns of both factors,meh-water input and evaporation output,still remain to be drawn.